Chemical Equilibrium Lab Report

At five minute intervals over the next fifteen minute period, record the color intensity of the solution of each test tube.

The main objective of this experiment is to differentiate between a physical change and a chemical change.

The first step that needed to be done in this experiment was adding hydrochloric acid (HCl)

After carefully taking them out, observe each test tubes color and then fill Table 2 with the results.

The objective of the experiment is to apply Le Chatelier's Principle, which is a system that responds to an external stress and then adjusts itself in order to alleviate the stress when it is at equilibrium. A reactant is added, and the equilibrium is reestablished, resulting in more products and fewer reactants, and thus, the position of equilibrium is shifted to the right. When a product is added, the equilibrium position is shifted to the left because there are more reactants and fewer products.

In 2 and 7 I added 50 mL of .1 M NaCl. I added sodium acetate to the rest of the beakers: 1 gram to 3 and 8, 5 grams to 4 and 9, and 10 grams to 5 and 10. I then filled the beakers that contained the solid sodium acetate with 50 ml of .10 M acetic acid. Specifics can be found on page 84 of the lab manual. Though the lab manual instructed to use a pipet, we did not have an accurate 1 mL pipet or a graduated pipet, so we instead prepared two graduated burets with 1 M Sodium Hydroxide and 1 M hydrochloric acid. Using a standardized pH probe with a Lab Pro to measure changes in pH, we added 1 mL of HCl at a time and recorded the changes. The same was done for the NaOH.

4. We observed the test tubes and compared the colors produced from the reaction to the color palette in 1 minute intervals for 5 minutes total.

1) Since the [OH⁻] would double, half the required number of drops would be needed.

This shows Le Chatelier’s principle as the system was able to neutralize the disturbance from its equilibrium.In this case, the change was the addition of molecules to the reactants. This caused an increase in the number effective collisions between the reactant’s molecules. Also, this raised the rate of the forward reaction. The system then has an increased amount of reactants and therefore has to travel in the forward direction to make extra products. This occurred in order to return the system to equilibrium by removing some of the excess reactants. By shifting in the forward direction, more products are being produced by the excess reactants. This ensures that the forward and reverse reaction rates are equal, which brings the system back to a state of

The lab was completed for two main reasons. The first reason was to determine the equilibrium constant for the

1) What is the surface area of each of your three cells? The agar cylinder had a surface area of 5.06 cm.

In order for the media to show the change in acidity the solutions are modified and include an indicator chemical. This indicator will change color depending on the ph level of the media it is in. For all the media used in this experiment, the indicator changes to a yellow color when in the presence of an acid and turns magenta/pink when in the presence of a base or alkali.

Add 4 drops of phenolphthalein in to the prepared acetic acid, and check whether the color changes to dark pink.

Chemical equilibrium is the study of change within a chemical reaction and how far it will go to reach a dynamic equilibrium (Burdge). Dynamic equilibrium is defined as the constant movement of species in a chemical reaction, gone to incompletion while the rates of production and consumption are equal (Kf = Kr ) (Burdge). It differs from static equilibrium in that species are constantly being consumed and produced, it is dynamic movement (Fox). The concentration of such species do not change, it remains constant (Fox). The rate at which species are being consumed and produced is known as the equilibrium constant (K) (Burdge). Due to the fact that the concentration

4. Spot the solution on a TLC plate and check with UV light to see